The present invention relates to an intermediate lens pad.
An example of such a lens pad is described and illustrated in GB-A-2039810. It is sandwiched between a lens tool and a surfacing pad, and adjusts the effective curvature of the tool. The surfacing pad may be secured to the intermediate pad either by adhesive or by friction grip.
A drawback of the use of adhesive is that it is difficult to remove the surfacing pad for a subsequent operation using the same tool. Whilst the friction grip method overcomes this problem, it can result in movement of the surfacing pad, so as to create defects in the curvature of the finished lens, and particles from the friction grip surface may work loose and possibly even scratch the surface of the lens.
It will be appreciated here that these problems arise regardless of whether the intermediate pad is a correcting pad. They arise as a result of the need to be able to change the surfacing pad.
The present invention seeks to provide a remedy.